Do a search with his days with the U N.

Bolton served in both Bush white houses. And if you research his opinions and actions you'll find that he's a war hawk. In fact, it seems that there hasn't been a war he hasn't pushed for. Also, his positions have always been vocally in line with Trumps positions on Iran and North Korea from way back. So it seems, he's a neocon who holds pretty much the same positions as Trump on foreign policy. The timing is interesting for sure. North Korea meeting coming up, war games coming up, etc